Nowadays, shredders are used to cut articles. If a relatively thick article whose thickness is beyond an acceptable range, for example a thick paper or a compact disc, is shredded, the thick article is readily jammed. Under this circumstance, the shredder has a usage problem or even a breakdown. For avoiding the occurrence of jamming, a thickness triggering device is mounted in the shredder to determine whether the article to be shredded is beyond the acceptable range.
Referring to FIG. 1, a schematic perspective view of a shredder having a thickness triggering device is illustrated. The shredder 100 includes an entrance 101, a shredding path 102, a movable element 103, a thickness sensing module 104, a driving assembly 105, a transmission gear set 106 and a shredding knife assembly 107.
The entrance 101 is disposed above the shredding path 102. The movable element 103 is arranged at a side of the shredding path 102. The thickness sensing module 104 is disposed behind the movable element 103. As shown in FIG. 1, the thickness sensing module 104 includes a first optical sensor 1041 and a second optical sensor 1042. The thickness sensing module 104 and the movable element 103 are cooperatively referred as a thickness triggering device.
The shredding knife assembly 107 is disposed at the outlet of the shredding path 102. The transmission gear set 106 is interconnected between and engaged with the shredding knife assembly 107 and the driving assembly 105. As a consequence, the shredding knife assembly 107 is driven by the driving assembly 105 to implement a shredding operation.
The operation of the shredder 100 will be illustrated as follows. First of all, an article (not shown) to be shredded is introduced into the shredding path 102 through the entrance 101. When the article is in contact with and sustained against the movable element 103, the movable element 103 is shifted backwardly to result in a shift distance with respect to its original place. The first optical sensor 1041 and the second optical sensor 1042 of the thickness sensing module 104 continuously emit sensing light. In a case that the sensing light is not sheltered by the movable element 103, the article is permitted to feed through the shredding path 102 so as to perform a shredding operation. Whereas, if the sensing light is sheltered by the movable element 103, the shredding operation of the shredder 100 is interrupted.
That is, in the case that the shift distance of the movable element 103 is not sufficient to fully shelter the sensing light emitted from the first optical sensor 1041 and the second optical sensor 1042, the thickness of the article is acceptable. Under this circumstance, the article is continuously advanced in the shredding path 102. In addition, the shredder 100 has a shredding sensor (not shown) under the movable element 103. The shredding sensor may be a general optical sensor for sensing the article. When the advancing article approaches the shredding knife assembly 107, the shredding sensor will detect the presence of the article. Meanwhile, the transmission gear set 106 is driven by the driving assembly 105 and begins to rotate. Upon rotation of the transmission gear set 106, the shredding knife assembly 107 is driven to the implement a shredding operation.
As previously described, by using the movable element 103 and the thickness sensing module 104, the usage status of the shredder 100 may be determined according to the thickness of the article to be shredded. In other words, the movable element 103 and the thickness sensing module 104 are advantageous of avoiding the problem of causing jammed paper so as to extend the operating life of the shredder 100. However, this shredder 100 still has some drawbacks. For example, during the shredding operation, the article is readily suffered from trembling and the trembling article may continuously touch the movable element 103. Even if the thickness of the article is within the acceptable range, the movable element 103 may fully shelter the sensing light emitted from the first optical sensor 1041 and the second optical sensor 1042. Under this circumstance, the shredder 100 is subject to interruption and the shredding operation is ceased.
Therefore, there is a need to provide a shredder which has a thickness triggering device and is capable of avoiding the trembling of the shredding article.